GB 25571-2011National food safety standard -- Food additives -- Activated clay (English PDF)

Foreword

This standard replaces GB 25571-2010 "national food safety standards for food additives activated clay." this standard compared with GB 25571-2010 main changes are as follows.

- Changes A.8.3 Analysis step.

This standard replaces the standards previously issued as follows.

--GB 25571-2010.

National Food Safety Standard Food additives activated clay

1 Scope

This standard applies to industrial sulfuric acid, water and bentonite as raw materials to produce food additives activated clay.

Formula 2

Al2O3 · 4SiO2 · nH2O

3 Technical requirements

3.1 Sensory requirements. comply with Table 1.

Table 1 Sensory requirements

Project requires test methods Color white or gray, pale pink proper amount of sample is placed in 50mL beaker, in natural light Observe the color and texture. Organization Status powder

3.2 Physical indicators. to comply with Table 2.

Table 2. Physical and chemical indicators

Item Index Test Method the specific surface area, m2/g >= 130 Appendix A A.4 Free acid (H2SO4 dollars), w /% <= 0.30 Appendix A A.5 Water, w /% <= 12.0 A.6 in Appendix A Fineness (0.075mm test sieve), w /% >= 90 Appendix A A.7 Filtration rate by testing in Appendix A A.8 Bulk density, g/mL 0.55 ± 0.10 A.9 Appendix A pH (50g/L suspension) of 2.2 to 4.8 A.10 Appendix A Heavy metals (Pb)/(mg/kg) <= 40 Appendix A A.11 Arsenic (As)/(mg/kg) <= 3 Appendix A A.12 Appendix A Testing method A.1 Warning Reagents The standard test methods used for toxic or corrosive, the operation should be careful as the water splashed on the skin should immediately Flushing, severe cases should be treated immediately.

A.2 General Provisions the standard test methods used in the reagents and water in the absence of other specified requirements, refer to analytically pure reagents and GB/T 6682-2008 in Three water regulations. Test with the standard titration solution, impurity standard solution, preparations and products, did not indicate when the other requirements, according HG/T 3696.1, HG/T 3696.2, the provisions of HG/T 3696.3 of preparation.

A.3 Identification

A.3.1 Reagents and materials A.3.1.1 potassium nitrate.

A.3.1.2 anhydrous sodium carbonate.

A.3.1.3 hydrochloric acid.

A.3.1.4 sodium hydroxide solution. 10mol/L;

Weigh 40g of sodium hydroxide dissolved in 100mL of water.

A.3.1.5 ammonium chloride solution. 2mol/L;

Weigh 10.7g ammonium chloride, dissolved in 100mL of water.

A.3.2 Identification Test Weigh about 0.5g sample in a metal crucible, was added 1g and 3g of anhydrous potassium carbonate, heated to a molten, cooled and 20mL boiling Water in the residue, stirred, and filtered. The residue was washed with 50mL, add hydrochloric acid 1mL, 5mL water in the residue and filtered. 1mL was added to the filtrate Sodium hydroxide solution, filtered, and the filtrate was added 3mL solution of ammonium chloride, there is gelatinous, white precipitate formed.

A.4 Determination of the specific surface area According to GB/T 19587 was measured.

A.5 Determination of free acid A.5.1 Reagents and materials A.5.1.1 sodium hydroxide standard titration solution. c (NaOH) = 0.02mol/L;

Pipette 50mL press HG/T 3696.1 formulated accurately known concentration of sodium hydroxide standard titration solution [c (NaOH) about 0.1mol/L], placed 250mL flask with carbon dioxide-free water to dilute to the mark.

A.5.1.2 phenolphthalein indicator solution. 10g/L.

A.5.2 Analysis step

Weigh about 2g samples, accurate to 0.000 2g, placed in 150mL beaker. Add 50mL water, boil 3min, in 250mL conical filter Flask with 50mL water and washed 4 to 5 times. The filtrate was all boiled 2min, covered with a rubber plug alkali asbestos drying tube, and cooled to room temperature.

Add 2 drops to 3 drops of phenolphthalein indicator solution, titration with sodium hydroxide standard titration solution to light red and holding 30s does not fade as the end point.

At the same time a blank test. But without addition of the sample, the other test reagent was added and the amount of the same, with the same sample processing.

A.5.3 Calculation Results Free acid content of sulfuric acid (H2SO4) mass fraction w1 and its value is expressed in%, according to formula (A.1) Calculated.

1000) (01

MVVc

Where.

Numerical sodium hydroxide standard titration solution consumed V1-- titration solution volume in milliliters (mL);

V0-- value titration blank test solution of sodium hydroxide standard titration solution volume consumed in milliliters (mL);

c - accurate sodium hydroxide standard titration solution concentration value in units of moles per liter (mol/L);

m - the value of the sample mass, in grams (g);

Numerical M-- sulfate (1/2 H2SO4) molar mass of the units of grams per mole (g/mol) (M = 49.00).

Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.04%.

A.6 Determination of Moisture A.6.1 Instruments and Equipment A.6.1.1 weighing bottle. Phi40mm × 25mm.

A.6.1.2 electric oven. temperature can be controlled at 105 °C ± 2 °C.

A.6.2 Analysis step

Weigh about 2g samples, accurate to 0.000 2g, previously placed at 105 °C ± 2 °C dried to constant mass weighing bottle and placed in an electric Thermostatic oven, at 105 °C ± 2 °C for drying to constant mass. Removed, placed in a desiccator to cool to room temperature, and weighed.

A.6.3 Calculation Results Moisture mass fraction w2 and its value is expressed in%, according to formula (A.2) Calculated.

012 ×

Where.

Numerical ago m-- dried sample mass, expressed in grams (g);

Value after m1-- dried sample mass, expressed in grams (g);

Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.5%.

A.7 Determination of fineness A.7.1 Instruments and Equipment Test sieves. R40/3 series, Phi200 × 50-0.075/0.050 (GB/T 6003.1 -1997).

A.7.2 Analysis step

It weighs about 20g sample to the nearest 0.01g. Exposed in a test sieve, constantly shaking, beating, and gently brushing with a dry brush, the sample by the end, the underlying black paper sieve, sieve lightly until the sample pad black paper no trace. The sieve residue transferred to a known mass Petri dish weighed to the nearest 0.000 2g.

A.7.3 Calculation Results Fineness mass fraction w3 and its value is expressed in%, according to formula (A.3) Calculated.

013 ×

Where.

Numerical m-- sample mass, expressed in grams (g);

Numerical quality m1-- sieve residue in grams (g).

Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 2%.

Determination A.8 filtration rate A.8.1 Reagents and materials Alkali refining soybean oil. soap containing not more than 0.004%.

A.8.2 Instruments and Equipment A.8.2.1 Buchner funnel. a diameter of 80mm.

A.8.2.2 vacuum pump.

A.8.3 Analysis step

Added 100.0g ± 0.1g in 400mL beaker alkali refining soybean oil, weighed 10.00g ± 0.01g sample was placed in alkali refining soybean oil, the beaker Moved to 100 °C constant temperature oil bath or water bath, stirring while heating 30min, at 20 °C ~ 25 °C laboratory temperature, hot medium speed qualitative filter paper Filtration (vacuum up to 5.3kPa) when the first drop of oil dropped suction bottles start time, when the end point of the cake appears dry, when used in the recording filter Room, no more than 10min filtered through experiments.

A.9 Determination of bulk density A.9.1 Instruments and Equipment A.9.1.1 bulk density measuring device material. glass, plastic, stainless steel.

A.9.1.2 bulk density measuring device. shown in Figure A.1. In mm 1-- tank;

2-- bracket;

3-- funnel

Figure A.1 bulk density measuring device

Determination A.9.1.3 tank volume the tank wash, dry, covered with glass, weighing bucket and quality of glass. Carefully pour water into the tank, nearly full when applied with a dropper Water to the full, covered with glass, with a filter paper and glass exterior of the tank water should be no air bubbles between the glass and the water tank. Reweighed Tank and quality of the glass sheet.

A.9.1.4 tank volume calculation Tank volume to V and its value is expressed in ml, by the formula (A.4) Calculated.

Water rho

21 Mm

Where.

Numerical and glass tank filled with water quality m1-- units of grams (g);

Numerical tank and glass quality m2-- not irrigation, in grams (g);

rho water - measured value at a temperature of water density, in grams per milliliter (g/mL).

A.9.2 Analysis step

Figure A.1 installed bulk density measuring device.

Weighing bucket quality, accurate to 0.1g.

Close the funnel at the bottom of the sample naturally filling, scrape up with a ruler part. Place the known mass of the tank, open at the end of the funnel, so try all material flow automatically into the feed tank (can also be bypassed with a glass rod), scrape up with a ruler part (do not move before gelling material tank), and the sample was weighed the quality of the bucket, accurate to 0.1g.

A.9.3 Calculation Results the bulk density rho mass per unit volume of the count, the value in grams per milliliter (g/mL) according to formula (A.5,) Calculated.

mm 21 - = rho (A.5)

Where.

Numerical ml-- tank and the sample mass, in grams (g);

Numerical m2-- tank mass in grams (g);

Numerical V-- tank volume in milliliters (mL).

Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.02g/mL.

Determination A.10 pH value A.10.1 instruments and equipment pH meter. dividing the value 0.02.

A.10.2 Analysis steps Weigh 5.00g ± 0.01g sample was placed in 150mL beaker, 100mL carbon dioxide-free water was added, after stirring for 1min, standing 5min. Use has been proofread acidimeter suspension pH.

Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.2.

A.11 Determination of Heavy Metals A.11.1 reagents and materials A.11.1.1 ascorbic acid.

A.11.1.2 hydrochloric acid solution. 14.

A.11.1.3 hydrochloric acid solution. 116.

A.11.1.4 ammonia solution. 14.

A.11.1.5 acetic acid - sodium acetate buffer solution. pH of about 3.

A.11.1.6 saturated hydrogen sulphide water (using now).

A.11.1.7 lead standard solution. 1mL solution containing lead (Pb) 0.020mg;

Pipette Pipette 2.00mL lead standard solution according to HG/T 3696.2 prepared, placed in 100mL volumetric flask, dilute to the mark, Shake well. The solution was formulated before use.

A.11.2 instruments and equipment Colorimetric tube. 50mL.

A.11.3 Analysis steps A.11.3.1 prepared test solution Weigh 10.00g ± 0.01g sample was placed in 150mL conical flask, add 50mL hydrochloric acid solution (A.11.1.2), lower the number of oscillations after boiling 10min, cooled, filtered in 100mL flask, each 10mL, washed with water, washed five times; diluted with water to the mark, this is a test Test solution A, Determination of Heavy Metals and Arsenic used.

Preparation A.11.3.2 standard colorimetric solution Pipette Pipette 2.00mL lead standard solution was placed in 50mL colorimetric tube, add 10mL water, aqueous ammonia solution or hydrochloric acid solution to adjust the pH About 2 (with a wide strip test). The following test solution simultaneously with the same treatment.

A.11.3.3 Determination Pipette Pipette 10.00mL A test solution into an evaporating dish and evaporated to dryness on a boiling water bath, was added 5mL hydrochloric acid solution (A.11.1.3) Dissolve, all transferred to 50mL colorimetric tube with aqueous ammonia solution to adjust the pH of about 2 (with a wide strip test). Plus 0.1g ascorbic acid, Dilution buffer solution 5mL, 10mL saturated hydrogen sulphide water, water to the mark. Place 10min in the dark. The color was not be deeper than the standard Associate color than the color of the solution.

A.12 Determination of Arsenic A.12.1 reagents and materials with GB/T 5009.76-2003 of Chapter 9.

A.12.2 instruments and equipment with GB/T 5009.76-2003 Chapter 10.

A.12.3 Analysis steps Pipette 5.00mL test solution A device placed in a given arsenic conical flask, add 4.5mL hydrochloric acid, following the same GB/T 5009.76-2003. 11 Chapter "Gutzeit from water to 30mL not be deeper than the limits of arsenic." Limits formulated solution. Pipette 1.50mL arsenic standard solution [1 mL solution containing 0.001mg of arsenic (As)], the following according to GB/T 5009.76-2003 Gutzeit method was measured. The following test solution simultaneously with the same treatment.